Tabun was originally discovered in 1937 by Gerhard Schrader of I.G.
Farben in Germany, through his research into pesticides based on
organophosphorous bondings. The word 'tabun' has no particluar meaning and was reportedly made up by Dr Schrader to disguise the discovery.
Tabun belongs to the G(erman)-class of nerve agents, codenamed GA. It was first produced industrially in 1942.

Pure Tabun is a colourless liquid with a fruity odour. The industrial product has a brownish color and has an
odour reminiscent of bitter almonds due to the formation of hydrogen cyanide. Tabun produced by the Germans generally
contained 5-20 percent chlorobenzene as solvent and
stabilizer.

The chemical name of Tabun is dimethylphosphoramidocyanidic acid, ethyl ester.
It has molecular formula C5H11N2O2P and formula weight 162.12
g/mol.

The first time Tabun or any other nerve agent was ever used in war was by Iraq against Iran
in 1984. Subsequently, its use was confirmed repeatedly until the end of the war in
1988.